1. Field of Invention
The present invention relates to a crossbow, and more particularly to a bow for a crossbow that can prolong the useful life of a limb of the crossbow and replace a worn-off pivot of the crossbow easily.
2. Description of the Related Art
With reference to FIG. 5, a conventional crossbow comprises a stock and a bow (70). The stock has a front end and a rear end. The bow (70) is mounted on the front end of the stock and comprises two retainers (71), two pockets (74), two limbs (72), and a string (73). The retainers (71) are mounted on the front end of the stock and each has a mounting surface and a semicircular recess (711) defined in the mounting surface of the retainer (71). The pockets (74) are mounted respectively on the mounting surfaces of the retainers (71) and each has a semicircular pivot (741). The semicircular pivots (741) are formed on the pocket (74) and are mounted respectively in the recesses (711) of the retainers (711). The limbs (72) are mounted respectively on the pockets (74) and each has a distal end. The string (73) is extended between the distal ends of the limbs (72).
When the string (73) of the conventional crossbow is stretched for projecting a bolt, the limbs (72) are bent toward the rear end of the stock and the pockets (74) are pivoted respectively relative to the retainers (71). Pivotal rotation of the pockets (74) is achieved easily by the rotation of the semicircular pivots (741) in the semicircular recesses (711).
However, after a long-term of use, the semicircular pivots (741) may be worn off because the force applied to the semicircular pivots (741) from the limbs (72) is quite large. When the semicircular pivots (741) are worn off, the pockets (74) must be replaced and discarded but this is rather uneconomical. In addition, when the limbs (72) are bent, cracks may occur gradually at the place where the limbs (72) abut with the pockets (741) because of stress concentration. The limbs (72) will break when the limbs (72) are unable to bear the force applied from the string (73), and this is very dangerous for a user and reduces the useful life of the crossbow.
To overcome the shortcomings, the present invention provides a bow for a crossbow to mitigate or obviate the aforementioned problems.